Coordinate-ordering for contour plotting

ABSTRACT

A COMPUTER PROGRAM TO DERIVED AND CONTROL PLOTTING OF CONTOUR REPRESENTING LINES OF CONSTANT VALUES WITHIN A LINEAR, 2-DIMENSIONAL MATRIX. THE PROGRAM USES AN ALGORITHM WHICH ORDERS COORDINATE OF POINTS ON A CONTOUR, ENABLING CONTINUOUS PROGRESSIONS ALONG THE CONTOUR. THE BASIC STEPS WITHIN THE CONTOUR ORDERING ALGORITHM MAY BE DEFINES, AS: (1) DETERMINATION OF AVAILABLE POINTS AS POTENTIAL CANDIDATES, (2) USE OF A SEARCH WINDOW TO DISCARD POINTS TOO REMOTE TO BE A VALID SUCCESSOR CANDIDATE, (3) CLASSIFYING SUCCESSOR CANDIDATES TO ENABLE SELECTION OF THE BEST ONE AS THE VALID SUCCESSOR, AND   (4) WHEN NO SUCCESSOR CANDIDATES ARE FOUND OR SELECTION OF THE BEST ONE CANNOT BE MADE, THE CONTOUR SEGMENT IS PROCESSED OR STORED, AND THE ALGORITHM PROCEED TO THE NEXT AVAILABLE STARTING POINT. THE PROGRAM CAN BE USED TO DETERMINED CLOSURE AND DISCRETE CONTOURS IN A SINGLE OR MULTIPLE CONTOUR ENVIRONMENT, WITH PARTICULAR APPLICATION TO PLOTTING AND ANALYSIS. THE INVENTION HEREIN DESCRIBED WAS MADE IN THE COURSE OR OR UNDER A CONTRACT OR SUBCONTRACT THEREUNDER WITH THE DEPARTMENT OF THE ARMY.

DEFENSIVE PUBLICATION UNITED STATES PATENT OFFICE Published at the request oi! the applicant or owner in accordance with the Notice 01 Dec. 16, 1969. 869 O.G. 687. The abstracts of Defensive Publication applications are identified by distinctly numbered series and are arranged chronologically.

The heading of each abstract indicates the number of pages of specification, including claims and sheets of drawings contained in the application as originally filed. The files of these applications are available to the public for inspection and reproduction may be purchased for 30 cents a sheet.

Defensive Publication applications have not been examined as to the merits of alleged invention. The Patent Oiiice makes no assertion as to the novelty of the disclosed subject matter.

PUBLISHED OCTOBER 9, 1973 T915,006 COORDINATE-ORDERING FOR CONTOUR PLOTTING Paul Arnold Friedman, Morristown, N.J., assignor to International Business Machines Corporation, Armonk,

Continiration of abandoned application Ser. No. 213,078, Dec. 28, 1971. This application Feb. 9, 1973, Ser.

Int. Cl. G06f 15/20 us. Cl. 444-1 4 Sheets Drawing. 34 Pages Specification A computer program to derive and control plotting of contour representing lines of constant values within a linear, Z-dimensional matrix. The program uses an algorithm which orders coordinate of points on a contour, enabling continuous progressions along the contour. The basic steps within the contour ordering algorithm may be defined as:

(1) determination of available points as potential candidates; (2) use of a search window to discard points too remote to be a valid successor candidate; (3) classifying successor candidates to enable selection of the best one as the valid successor; and

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comoua 3 4 (4) when no successor candidates are found or selection of the best one cannot be made, the contour segment is processed or stored, and the algorithm proceed to the next available starting point.

The program can be used to determine closure and discrete contours in a single or multiple contour environment, with particular application to plotting and analysis. The invention herein described was made in the course of or under a contract or subcontract thereunder with the f Department of the Army.

Oct. 9, 1973 P. A. FRIEDMAN T915,006

COORDINATE-ORDERING FOR CONTOUR PLOTTING 4 Sheets-Sheet 1 Original Filed Dec. 28, 1971 FIG.1

FIG. 2

FY 88 r O FX 68 [IV EIV e 8 F(X,Y CONTOUR VALUE Get. 9, 1973 P. A. FRIEDMAN COORDINATE-ORDERING FOR CONTOUR PLO'ITING 4 Sheets-Sheet 2 Original Filed Dec. 28, 1971 FIG. 4

F(X,Y CONTOUR F(X,Y) CONTOUR FIG. 5

Oct. 9, 1973 p A, FRIEDMAN T9l5,006

COORDINATE-ORDERING FOR CONTOUR PLOTTING I Original Filed Dec. 28, 1971 4 Sheets-Sheet 5 FIG. 60

P A RNNENE R s SUBROUT'NE AND 4 mm PLOTTING GRID mums PASS-1 TO END OR MULTIPLE SUCCESSORS 2ND PASS-GENERATES CLOSURES AND RESOLVED SUCCESSIONS 3RD PASS-CENERATES ALL POSSIBLE REMAINING CONNECTIONS USED I PASS PASS 1 FIND 1ST POINT ON NEXT CURVE STORE NEXT POINT AND ,8 INCRE MENT COUNTERS IN ITIALIZE FOR NEXT POINT, SET WINDOW Oct. 9, 1973 A. FRIEDMAN COQRDTNATE-ORDERING FOR CONTOUR PLOTTING 4 Sheets-Sheet 4 Original Filed Dec. 28 1971 FIND NEXT SUCCESSDR CANDIDATE VALID SUCCESSCR IN WINDOW AND CURRENT 4 POINT 5RD PASS PL FIRST SUBROUTINE NTYPE 1 SAVE CLDSEST TYPE 1 POINT NTYPE 2 INCREMENT coum I T SAVE POINT I69 MORE SUCCESSOR CANDIDATES SUBRDUTINE PLOT CURVE TPLOT N0 STORE PAIR PARAMETERS YES 

